1. Field of the Invention
The present invention relates to an ink tank cartridge and an ink jet recording apparatus using same.
2. Description of the Related Art
In the prior art, there have been proposed recording apparatuses for recording on recording media such as paper or sheets for overhead projectors (hereinafter referred to as recording paper or simply paper), in which recording heads are installed by various recording methods. These recording methods can be either a wire dot, a thermal, a thermal transfer, or an ink jet method. In the ink jet method, for example, recording is performed by directly discharging ink onto recording paper. The running cost is low and this method, which provides virtually noiseless recording, has attracted a great deal of attention lately.
Recording apparatuses using an ink jet method are broadly classified into the following two types: one in which a recording head and an ink supply tank are made into a single unit that can be replaced; and one in which a recording head and an ink supply tank are constructed separately, the ink supply tank producing an ink supply source to compensate for the loss of ink due to recording and being detachably mounted in the main body of the apparatus for replacement by the user.
In the latter type of ink tank, ink is housed in a sealed flexible bag of an aluminum-laminate material or the like to prevent changes in the ink due to irradiation of light, entry of air or other gases that can affect ink supply and leakage of ink to the environment and also to balance the internal pressure of the ink supply system. The ink bag is typically housed in a box-shaped housing for ease of handling of the cartridge into which it is incorporated. A stopper formed of an elastic member, such as rubber, is mounted in the ink bag and a hollow needle member disposed in the ink supply system of the ink jet recording apparatus's main body is inserted through the stopper to supply ink to the recording head.
However, in the ink cartridge described above, a problem sometimes occurs depending upon how a cartridge is handled when it is detached from the apparatus's main body. For example, in a cartridge loaded in the apparatus for a long period of time, a stopper formed of rubber may deteriorate due to aging. In this case, the hole through which the hollow needle member was inserted may not be completely sealed when the cartridge is removed from the apparatus. In this condition, the small amount of ink that has not been completely discharged from the bag can leak from the through hole of the stopper. Hence, the inside of the recording apparatus (particularly the cartridge housing section) and the operator's hands can be soiled when the cartridge is removed from the apparatus. In addition, when the cartridge is disposed of, ink may be undesirably released to the environment. Leakage from the ink bag can be exacerbated initially expanded to almost fully occupy the space inside the housing, but when it contracts as the ink is consumed, it can move inside the housing and cause ink to squirt from the hole of the stopper.